Asset Retirement Obligations (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	$ 628
Incurred	0
Settled	(30)
Accretion	20
Cash Flow Revisions	129
ARO Liability, end of period	747
Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	605
Incurred	0
Settled	(30)
Accretion	19
Cash Flow Revisions	129
ARO Liability, end of period	723
Renewable generation assets
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	23
Incurred	0
Settled	0
Accretion	1
Cash Flow Revisions	0
ARO Liability, end of period	24
Renewable generation assets | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	93
Incurred	0
Settled	0
Accretion	2
Cash Flow Revisions	0
ARO Liability, end of period	95
Coal ash disposal areas | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	157
Incurred	0
Settled	(17)
Accretion	4
Cash Flow Revisions	129
ARO Liability, end of period	273
Gas distribution cut, purge, and cap | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	282
Incurred	0
Settled	(10)
Accretion	11
Cash Flow Revisions	0
ARO Liability, end of period	283
Asbestos abatement | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	38
Incurred	0
Settled	(1)
Accretion	1
Cash Flow Revisions	0
ARO Liability, end of period	38
Gas wells plug and abandon | Consumers Energy Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO Liability, at beginning of period	35
Incurred	0
Settled	(2)
Accretion	1
Cash Flow Revisions	0
ARO Liability, end of period	$ 34